1. Field of the Invention
The present invention relates to a confocal microscope for confocal observation of a specimen.
2. Description of the Related Art
In a confocal microscope, illumination light is concentrated at one point of a specimen. The intensity of light emitted from the point is measured by a sensor. The same operation is repeated while the measured point is two-dimensionally scanned on the specimen. Thus, an image intensity distribution of the specimen is obtainable with high resolution, enabling confocal observation. To effectively perform the confocal observation, there has been proposed a multi-point scanning system using a Nipkow disc, for example (for example, refer to Japanese Unexamined Patent Application Publication No. Hei 9-325279). In this case, adjacent measured points are set with an interval in accordance with an interval of adjacent pinholes of the Nipkow disc, thereby preventing light emitted from the measured points from mixing each other on the sensor (namely, a confocal effect is maintained).
However, the multi-point scanning system has a problem of low light use efficiency since the aperture ratio of pinholes of the Nipkow disc is low, so that among light emitted from a light source, only a small amount of light that passes through the pinholes illuminates a specimen.